Has anyone tried this? I do plan on doing LT's and mid-pipe but in the mean time I considered just doing a shortened X/H w/ hi-flow cats? By shortened I mean adding in a couple of lengths of 2.5" tubing to be removed when the LT's go in.

Here's what I'm talking about

 

Take a look at the Mac x-pipe and also the Hooker x-pipe. I think they sort of do what you are planning.